WASET
    Yongxin Yuan and  Jiashang Jiang,  A New Direct Updating Method for Undamped Structural Systems.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    January 2010, vol. 37(1). 1 - 6
    [viewed 25 April 2024]. Available from: https://publications.waset.org/pdf/11823.